A prosthesis limb replaces a missing extremity, such as an arm or a leg and may be needed for a variety of reasons, including diseases, and accidents. An artificial limb may also be needed when a person is born with a missing or damaged limb(s). The type of prosthesis limb used is determined largely by the extent of an amputation or loss and location of the missing limb. A transtibial prosthesis is an artificial leg that is attached to a user below the knee and includes a lower leg, ankle and foot. The transfemoral prosthesis is an artificial leg that is attached to the user's amputated limb above the knee and includes an upper leg and mechanical knee. A transradial prosthesis is an artificial arm that is attached to the user below the elbow and includes a forearm and hand. A transhumeral prosthesis is an artificial arm that is attached to the user above the elbow.
In developing areas of the world, including large portions of Africa, the leading causes of amputations are industrial, vehicular, and war related accidents. In more developed areas, such as North America and Europe, the leading causes for the amputations are diseases including cancer, infection and circulatory. In the United States, approximately 100,000 legs are lost each year to diabetes, vascular disorder, accidents and cancer. Because there are so many amputations, there is a substantial need for prosthetic limbs.
The engineering of prosthetic limbs has improved greatly. In particular, artificial knees and feet have been developed for prosthetic legs that provide increased mobility and functionality. While the engineering and mechanics of prosthetic limbs have evolved greatly, very little thought has been given to the aesthetics of the human being for whom the device was intended. With reference to FIG. 1, a modern prosthetic leg 101 is shown having a socket 121 that has a recessed surface that engages the end of the user's amputated leg. The socket 121 is typically a padded plastic structure that distributes the compression forces on the end of the amputated limb. The bottom of the socket 121 is attached to a pylon 123 which is a tubular support that can be made of titanium or aluminum. The pylon can be manufactured through an extrusion process. The bottom of the pylon 123 is attached to an artificial foot 125 that can be a molded plastic structure. The prosthetic leg 101 may also have a foam covering 127 and can be attached to the socket 121 and pylon 123 to provide a more uniform shape. The various socket 121, pylon 123 and foot 125 can be coupled together using fasteners including bolts, screws and adhesives.
A problem with the existing prosthetic limbs is that they are not readily available to people who live in remote parts of the world. Many of these people do not have access to prosthetic limb manufacturers. Also, since prosthetic limbs are very expensive, many people do not have the financial resources to purchase them. Without these resources, the amputees cannot obtain properly designed prosthetic limbs and may rely upon other devices for mobility such as crutches or wheelchairs. One shortcoming of a lower-quality leg is a knee that consists of a basic hinge. While this does allow upper and lower leg to rotate similar to a human leg, the knee does not lock out with each stride, increasing the risk of a fall or uncertain step. While these devices provide basic mobility, they are not as practical as prosthetic limbs since they require the use of arms. Thus, the user cannot use his or her arms while moving. What is needed is a more cost effective prosthetic limb that can be built for patients with minimal equipment.